Method for Operating a High-Density Solids Pump and High-Density Solids Pump

ABSTRACT

A method operates a thick-matter pump having a thick-matter delivery system and a hydraulic drive system. The thick-matter delivery system delivers thick matter with a variably settable delivery volumetric flow rate for driving the thick-matter delivery system. The hydraulic drive system has: a hydraulic circuit having a hydraulic fluid, a variably operable first drive pump, and a variably operable second drive pump. The first drive pump is designed for variable operation with at least one variably settable first pump parameter and the second drive pump is designed for variable operation, independent of the first pump parameter, with at least one variably settable second pump parameter for generating a variably settable overall drive volumetric flow rate of the hydraulic fluid in the hydraulic circuit. The method determines an overall-drive-volumetric-flow-rate target value for the overall drive volumetric flow rate, and determines a first parameter target value for the first pump parameter and a second parameter target value for the second pump parameter in a manner dependent on the determined overall-drive-volumetric-flow-rate target value. The first and second parameter target values differ from one another if the determined overall-drive-volumetric-flow-rate target value is in at least one overall-drive-volumetric-flow-rate-target-value range from a set of possible overall-drive-volumetric-flow-rate target values. The method delivers the thick matter with the delivery volumetric flow rate at a delivery-volumetric-flow-rate target value by generating the overall drive volumetric flow rate with the determined overall-drive-volumetric-flow-rate target value by setting the first pump parameter to the determined first parameter target value and the second pump parameter to the determined second parameter target value.

FIELD OF APPLICATION

The invention relates to a method for operating a thick-matter pump, and to a thick-matter pump.

Problem and Solution

The invention is based on the problem of providing a method for operating a thick-matter pump and a thick-matter pump that in each case have improved properties.

The invention solves this problem through the provision of a method and a thick-matter pump having the features of the independent claims. Advantageous refinements and/or configurations of the invention are described in the dependent claims.

The, in particular automatic, method according to the invention is designed or configured for, in particular automatic, operation of a thick-matter pump. The thick-matter pump comprises or has a thick-matter delivery system and a hydraulic drive system. The thick-matter delivery system is designed or configured for delivering thick matter with a variably settable delivery volumetric flow rate, in particular delivery-volumetric-flow-rate value. The hydraulic drive system comprises or has, for driving the thick-matter delivery system, a, in particular common, hydraulic circuit having or comprising a hydraulic fluid, a variably operable first drive pump and a variably operable second drive pump. Here, the first drive pump is designed or configured for variable operation with at least one variably settable first pump parameter, in particular pump parameter value, and the second drive pump is designed or configured for variable operation, independent of the first pump parameter, with at least one variably settable second pump parameter, in particular pump parameter value, for generating, in particular indirectly, a variably settable overall drive volumetric flow rate, in particular overall-drive-volumetric-flow-rate value, or total drive volumetric flow rate of the hydraulic fluid in the, in particular identical, hydraulic circuit. The method comprises the following steps: determining, in particular automatically determining, an overall-drive-volumetric-flow-rate target value for the overall drive volumetric flow rate; determining, in particular automatically determining, a first parameter target value for the first pump parameter and a second parameter target value for the second pump parameter in a manner dependent on, in particular at least, the determined overall-drive-volumetric-flow-rate target value, where the first parameter target value and the second parameter target value differ from one another if the determined overall-drive-volumetric-flow-rate target value is in at least one overall-drive-volumetric-flow-rate-target-value range from a set of possible overall-drive-volumetric-flow-rate target values; delivering the thick matter with the delivery volumetric flow rate at a delivery-volumetric-flow-rate target value by means of generating the overall drive volumetric flow rate with the determined overall-drive-volumetric-flow-rate target value by means of, in particular automatically, setting the first pump parameter to the determined first parameter target value and the second pump parameter to the determined second parameter target value.

This makes it possible, in particular the first parameter target value and the second parameter target value differing from one another make it possible, for the thick-matter pump to be operated more optimally, in particular by contrast to a method not according to the invention for operating a thick-matter pump wherein the first parameter target value and the second parameter target value are equal to one another for all possible overall-drive-volumetric-flow-rate target values.

In particular, the at least one overall-drive-volumetric-flow-rate-target-value range with the first parameter target value and the second parameter target value differing from one another may have or comprise at least one overall-drive-volumetric-flow-rate target value.

In particular, the at least one overall-drive-volumetric-flow-rate-target-value range with the first parameter target value and the second parameter target value differing from one another may be at least 20 percent (%), in particular at least 30%, in particular at least 40%, and/or at most 100%, of the set of possible overall-drive-volumetric-flow-rate target values. In addition or as an alternative, the first parameter target value and the second parameter target value may be equal to one another if the determined overall-drive-volumetric-flow-rate target value is in at least one other overall-drive-volumetric-flow-rate-target-value range from the set of possible overall-drive-volumetric-flow-rate target values. Also in addition or as an alternative, there is no need to determine that or whether the determined overall-drive-volumetric-flow-rate target value is in the at least one overall-drive-volumetric-flow-rate-target-value range from the set of possible overall-drive-volumetric-flow-rate target values.

The first pump parameter or the first parameter target value and the second pump parameter or the second parameter target value may be comparable or similar or of the same type or have the same unit, in particular dimensional unit.

The values, in particular target values, may in each case be in a, in particular absolute, dimensional unit or in a relative unit, in particular in %, in particular bounded by a minimum value of 0% and a maximum value of 100%.

Variably settable may be referred to as adjustable or changeable, and/or variable setting may be referred as adjustment or change, and/or variably operable drive pump may be referred to as variable displacement pump. In addition or as an alternative, variably settable may mean settable, in particular in a continuously adjustable manner, to at least three different values, and/or variable setting may mean setting, in particular in a continuously adjustable manner, to one of at least three different values. Also in addition or as an alternative, in the case of a change of the overall-drive-volumetric-flow-rate target value, the first parameter target value and/or the second parameter target value may be changed or adjusted or set differently.

The overall-drive-volumetric-flow-rate target value may be specified by a user or an operator of the thick-matter pump.

The overall drive volumetric flow rate of the hydraulic fluid may be generated in a drive-pressure section, in particular a drive-high-pressure section, of the hydraulic circuit. In addition or as an alternative, the first drive pump and the second drive pump may be coupled to one another.

The hydraulic fluid may comprise, in particular be, oil.

The thick-matter pump may be a building-material pump. In addition or as an alternative, the thick-matter delivery system may be designed for delivering thick matter in the form of building material. Building material may refer to mortar, cement, screed, concrete and/or plaster. Also in addition or as an alternative, thick matter may refer to sludge.

In one refinement of the invention, the method comprises the step of: determining, in particular automatically determining, in particular detecting, the delivery-volumetric-flow-rate target value for the delivery volumetric flow rate. The method comprises: determining the overall-drive-volumetric-flow-rate target value in a manner dependent on the determined delivery-volumetric-flow-rate target value. In particular, the delivery-volumetric-flow-rate target value may be specified by the user of the thick-matter pump.

In one refinement of the invention, the method comprises the step of: detecting, in particular automatically detecting, a drive-pressure actual value of a drive pressure, in particular of a drive high pressure, of the hydraulic fluid in the hydraulic circuit. The drive-pressure actual value of the drive pressure is established in a manner dependent on a delivery-pressure actual value of a delivery pressure of the thick matter at the time of or during delivery.

The method comprises: determining the first parameter target value and the second parameter target value in a manner dependent on the detected drive-pressure actual value. This, in particular the detection of the first parameter target value and the second parameter target value in a manner dependent on the detected drive-pressure actual value, makes it possible for the thick-matter pump to be operated even more optimally, in particular by contrast to a method not according to the invention for operating a thick-matter pump wherein the first parameter target value and the second parameter target value are not determined in a manner dependent on a drive-pressure actual value. In particular, the delivery-pressure actual value may be established at the time of delivery, in particular and may be changed at the time of or during delivery, in a manner dependent on a consistency of the thick matter and/or on a boom position of a distribution boom (if provided) of the thick-matter pump. In addition or as an alternative, the hydraulic drive system, in particular the first drive pump and the second drive pump, may be designed or configured in such a way that the drive-pressure actual value can be established. Also in addition or as an alternative, in the case of a change of the drive-pressure actual value, the first parameter target value and/or the second parameter target value may be changed or adjusted or set differently. Also in addition or as an alternative, the drive pressure may be in a drive-pressure section, in particular the drive high pressure may be in a drive-high-pressure section, of the hydraulic circuit.

In one refinement of the invention, the thick-matter pump comprises or has at least, in particular only, one, in particular a single, drive motor. The at least one drive motor is designed or configured for rotating the first drive pump and the second drive pump for generating the overall drive volumetric flow rate. The method comprises: delivering the thick matter by means of rotating the first drive pump and the second drive pump by means of the at least one drive motor.

In one refinement of the invention, the first drive pump is designed or configured for variable rotation with the first pump parameter, in the form of a variably settable first pump rotational speed, and the second drive pump is designed or configured for variable rotation, independent of the first pump rotational speed, with the second pump parameter, in the form of a variably settable second pump rotational speed. In particular, the first parameter target value, in the form of a first pump-rotational-speed target value, and the second parameter target value, in the form of a second pump-rotational-speed target value, differ from one another if the determined overall-drive-volumetric-flow-rate target value is in the at least one overall-drive-volumetric-flow-rate-target-value range. In addition or as an alternative, the method comprises: delivering the thick matter by means of setting the first pump rotational speed to the determined first pump-rotational-speed target value and the second pump rotational speed to the determined second pump-rotational-speed target value. Also in addition or as an alternative, the thick-matter pump may have at least one variably settable transmission, wherein the at least one variably settable transmission can connect the, in particular only, drive motor to the first drive pump and/or to the second drive pump for the purpose of rotation. This can make possible the independence of the first pump rotational speed and the second pump rotational speed from one another.

In one configuration of the invention, the thick-matter pump comprises or has a variably operable first drive motor and a second drive motor which can be operated variably independently of the first drive motor. Here, the first drive motor is designed or configured for variably rotating the first drive pump, and the second drive motor is designed or configured for variably rotating the second drive pump. This makes it possible for the thick-matter pump not to need to have a variably settable transmission. In particular, the first drive motor may be designed for variably setting its first motor rotational speed, and/or the second drive motor may be designed for variably setting, in particular independently of the first motor rotational speed, its second motor rotational speed. In addition or as an alternative, the first drive motor need not be designed for variable rotation of the second drive pump and/or the second drive motor need not be designed for variable rotation of the first drive pump.

In one configuration of the invention, the first drive motor and the second drive motor each comprise or have an electric drive motor. In particular, the first drive motor and the second drive motor are each an electric drive motor. In particular, the electric drive motor may be a synchronous motor, in particular having an assigned frequency converter of the thick-matter pump.

In one configuration of the invention, the, in particular only, drive motor comprises or has a combustion drive motor. In particular, the, in particular only, drive motor is a combustion drive motor. In particular, the combustion drive motor may have, in particular be, a diesel drive motor.

In one refinement of the invention, the first drive pump, in the form of a first axial piston pump having or comprising a variably settable first sliding disk or swashplate, is designed or configured for variably setting the first pump parameter, in the form of a first pivot angle of the first sliding disk, and the second drive pump, in the form of a second axial piston pump having or comprising a variably settable second sliding disk or swashplate, is designed or configured for variably setting, independently of the first pivot angle, the second pump parameter, in the form of a second pivot angle of the second sliding disk. This makes it possible for the thick-matter pump to be able to have only a single drive motor and/or not to need to have a variably settable transmission. In particular, the first drive pump and the second drive pump may be designed for, in particular variable, rotation with a fixed or not variably settable pump-rotational-speed ratio, in particular an equal, in particular variably settable, pump rotational speed. In addition or as an alternative, the first parameter target value, in the form of a first pivot-angle target value, and the second parameter target value, in the form of a second pivot-angle target value, differ from one another if the determined overall-drive-volumetric-flow-rate target value is in the at least one overall-drive-volumetric-flow-rate-target-value range. Also in addition or as an alternative, the method comprises: delivering the thick matter by means of setting the first pivot angle to the determined first pivot-angle target value and the second pivot angle to the determined second pivot-angle target value. Also in addition or as an alternative, the method may comprise: determining the first parameter target value, in the form of the first pivot-angle target value, and the second parameter target value, in the form of the second pivot-angle target value, in a manner dependent on a motor-rotational-speed value, in particular a motor-rotational-speed actual value, of the drive motor.

In one configuration of the invention, the, in particular only, drive motor is designed or configured for variably setting its motor rotational speed. The method comprises the following step: determining, in particular automatically determining, a motor-rotational-speed target value for the motor rotational speed in a manner dependent on the determined overall-drive-volumetric-flow-rate target value, in particular and on the detected drive-pressure actual value (if provided). The method comprises: delivering the thick matter by means of, in particular automatically, setting the motor rotational speed to the determined motor-rotational-speed target value.

In one configuration of the invention, with increasing overall-drive-volumetric-flow-rate target value in a low overall-drive-volumetric-flow-rate-target-value range, a first pivot-angle target value for the first pivot angle increases, in particular from a first pivot-angle minimum value, in particular zero, up to a first pivot-angle maximum value and a second pivot-angle target value for the second pivot angle is constant, in particular a second pivot-angle minimum value, in particular zero, in a higher overall-drive-volumetric-flow-rate-target-value range, the second pivot-angle target value increases, in particular from the second pivot-angle minimum value, in particular zero, up to a second pivot-angle maximum value, in particular and if the first pivot-angle target value is the first pivot-angle maximum value and the second pivot-angle target value is the second pivot-angle maximum value, and in an even higher overall-drive-volumetric-flow-rate-target-value range, the motor-rotational-speed target value increases from a motor-rotational-speed minimum value, in particular greater than zero, up to a motor-rotational-speed maximum value. This makes possible a maximum efficiency of the hydraulic system. In particular, in the low overall-drive-volumetric-flow-rate-target-value range and/or the higher overall-drive-volumetric-flow-rate-target-value range, the motor-rotational-speed target value may be constant, in particular the motor-rotational-speed minimum value, in particular greater than zero. In addition or as an alternative, the first pivot-angle minimum value and the second pivot-angle minimum value may be equal, and/or the first pivot-angle maximum value and the second pivot-angle maximum value may be equal. Also in addition or as an alternative, the second axial piston pump may generate at the second pivot-angle maximum value an overall-drive-volumetric-flow-rate value of the overall drive volumetric flow rate that is equal to that which the first axial piston pump generates at the first pivot-angle maximum value, in particular at an equal rotational speed.

In one configuration of the invention, the second axial piston pump, in particular by itself, generates at a second pivot-angle maximum value of the second pivot angle an overall-drive-volumetric-flow-rate value of the overall drive volumetric flow rate that is greater than that which the first axial piston pump, in particular by itself, generates at a first pivot-angle maximum value of the first pivot angle, in particular at an equal rotational speed. With increasing overall-drive-volumetric-flow-rate target value in a low overall-drive-volumetric-flow-rate-target-value range, a first pivot-angle target value for the first pivot angle is greater than a second pivot-angle target value for the second pivot angle up to the first pivot-angle maximum value, in a higher overall-drive-volumetric-flow-rate-target-value range, the second pivot-angle target value is greater than the first pivot-angle target value up to the second pivot-angle maximum value, in particular and if the first pivot-angle target value is the first pivot-angle maximum value and the second pivot-angle target value is the second pivot-angle maximum value, and in an even higher overall-drive-volumetric-flow-rate-target-value range, the motor-rotational-speed target value increases from a motor-rotational-speed minimum value up to a motor-rotational-speed maximum value. This makes possible a maximum efficiency of the hydraulic system. In other words: the second axial piston pump may have a higher maximum displacement volume than the first axial piston pump. In particular, in the low overall-drive-volumetric-flow-rate-target-value range and/or the higher overall-drive-volumetric-flow-rate-target-value range, the motor-rotational-speed target value may be constant, in particular the motor-rotational-speed minimum value, in particular greater than zero. In addition or as an alternative, the first pivot-angle maximum value and the second pivot-angle maximum value may be equal.

In one refinement, in particular one configuration, of the invention, the method comprises: determining the first parameter target value and the second parameter target value, in particular and the motor-rotational-speed target value (if provided), on the basis of an optimization criterion. The optimization criterion is a maximum efficiency of the thick-matter pump, in particular a maximum efficiency of the hydraulic drive system, in particular a maximum efficiency of the first drive pump and/or a maximum efficiency of the second drive pump, or a minimum energy consumption, in particular a minimum fuel consumption, and/or a maximum efficiency of the at least one drive motor. In particular, the optimization criterion may be specified by the user of the thick-matter pump.

In one refinement of the invention, the first drive pump and the second drive pump are arranged in parallel in the hydraulic circuit. In addition or as an alternative, the hydraulic drive system comprises or has a, in particular at least one, variably movable drive piston in the hydraulic circuit for driving the thick-matter delivery system. The first drive pump and the second drive pump are designed or configured for generating the variably settable overall drive volumetric flow rate of the hydraulic fluid in the hydraulic circuit for variably moving the, in particular at least one, drive piston. The method comprises: delivering the thick matter by means of variably moving the drive piston. In particular, the first parameter target value and the second parameter target value may, at the time of or during a stroke, in particular for at least 50% of a length and/or duration of the stroke, differ from one another, in particular and not only with respect to a change in a direction of movement of the drive piston.

The thick-matter pump according to the invention has a, in particular the, thick-matter delivery system, a, in particular the, hydraulic drive system, and a, in particular electrical, determination device. The thick-matter delivery system is designed for delivering thick matter, in particular the thick matter, with a, in particular the, variably settable delivery volumetric flow rate. The hydraulic drive system has, for driving the thick-matter delivery system, a, in particular the, hydraulic circuit having a, in particular the, hydraulic fluid, a, in particular the, variably operable first drive pump and a, in particular the, variably operable second drive pump. Here, the first drive pump is designed for variable operation with at least one, in particular the at least one, variably settable first pump parameter and the second drive pump is designed for variable operation, independent of the first pump parameter, with at least one, in particular the at least one, variably settable second pump parameter for generating a, in particular the, variably settable overall drive volumetric flow rate of the hydraulic fluid in the hydraulic circuit. The determination device is designed or configured for, in particular automatically, determining an, in particular the, overall-drive-volumetric-flow-rate target value for the overall drive volumetric flow rate. Furthermore, the determination device is designed or configured for, in particular automatically, determining a, in particular the, first parameter target value for the first pump parameter and a, in particular the, second parameter target value for the second pump parameter in a manner dependent on the determined overall-drive-volumetric-flow-rate target value. Here, the first parameter target value and the second parameter target value differ from one another if the determined overall-drive-volumetric-flow-rate target value is in at least one, in particular the at least one, overall-drive-volumetric-flow-rate-target-value range from a, in particular the, set of possible overall-drive-volumetric-flow-rate target values. The thick-matter pump is designed or configured for delivering the thick matter with the delivery volumetric flow rate at a, in particular the, delivery-volumetric-flow-rate target value by means of generating the overall drive volumetric flow rate with the determined overall-drive-volumetric-flow-rate target value by means of, in particular automatically, setting the first pump parameter to the determined first parameter target value and the second pump parameter to the determined second parameter target value.

The thick-matter pump may allow the same advantages as the method described above.

In particular, the thick-matter pump may be designed or configured for carrying out the method described above.

The determination device may have a processor and/or a memory.

Further advantages and aspects of the invention emerge from the claims and from the following description of preferred exemplary embodiments of the invention, which are discussed below on the basis of the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic circuit diagram of a thick-matter pump according to an embodiment of the invention having only a single drive motor.

FIG. 2 is a schematic circuit diagram of a detail of a thick-matter pump according to an embodiment of the invention having a first drive motor and having a second drive motor.

FIG. 3 is a flow diagram of an exemplary method for operating the thick-matter pump by means of a look-up table.

FIG. 4 is a flow diagram for determining the look-up table in FIG. 3 .

FIG. 5 is a flow diagram of an exemplary method for operating the thick-matter pump by means of online determination.

FIG. 6 is a graph of a first parameter target value in the form of a first pivot-angle target value, a second parameter target value in the form of a second pivot-angle target value, and a motor-rotational-speed target value, versus an increasing overall-drive-volumetric-flow-rate target value of the method.

FIG. 7 is a further graph of a first parameter target value in the form of a first pivot-angle target value, a second parameter target value in the form of a second pivot-angle target value, and a motor-rotational-speed target value, versus an increasing overall-drive-volumetric-flow-rate target value of the method.

DETAILED DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 show a thick-matter pump 1. The thick-matter pump 1 has a thick-matter delivery system 2, a hydraulic drive system 3 and a determination device 50. The thick-matter delivery system 2 is designed for delivering thick matter DS with a variably settable delivery volumetric flow rate QF. The hydraulic drive system 3 has, for driving the thick-matter delivery system 2, a hydraulic circuit 4 having a hydraulic fluid HF, a variably operable first drive pump 5 and a variably operable second drive pump 7. Here, the first drive pump 5 is designed for variable operation with at least one variably settable first pump parameter P5 and the second drive pump 7 is designed for variable operation, independent of the first pump parameter P5, with at least one variably settable second pump parameter P7 for generating a variably settable overall drive volumetric flow rate QA of the hydraulic fluid HF in the hydraulic circuit 4. The determination device 50 is designed for determining an overall-drive-volumetric-flow-rate target value QAS for the overall drive volumetric flow rate QA, as shown in FIGS. 3 and 5 . Furthermore, the determination device 50 is designed for determining a first parameter target value P5S for the first pump parameter P5 and a second parameter target value P7S for the second pump parameter P7 in a manner dependent on the determined overall-drive-volumetric-flow-rate target value QAS. The first parameter target value P5S and the second parameter target value P7S differ from one another if the determined overall-drive-volumetric-flow-rate target value QAS is in at least one overall-drive-volumetric-flow-rate-target-value range QASB1, QASB2, QASB3, QASB1′ from a set 0, QASB1, QASB2, QASB3, QASB4, QASB1′, QASB2′, QASB3′ of possible overall-drive-volumetric-flow-rate target values QAS, as shown in FIGS. 6 and 7 . The thick-matter pump 1 is designed for delivering the thick matter DS with the delivery volumetric flow rate QF at a delivery-volumetric-flow-rate target value QFS by means of generating the overall drive volumetric flow rate QA with the determined overall-drive-volumetric-flow-rate target value QAS by means of setting the first pump parameter P5 to the determined first parameter target value P5S and the second pump parameter P7 to the determined second parameter target value P7S.

FIGS. 3 and 5 show a method for operating the thick-matter pump 1. The thick-matter pump 1 has the thick-matter delivery system 2 and the hydraulic drive system 3. The thick-matter delivery system 2 is designed for delivering the thick matter DS with the variably settable delivery volumetric flow rate QF. The hydraulic drive system 3 has, for driving the thick-matter delivery system 2, the hydraulic circuit 4 having the hydraulic fluid HF, the variably operable first drive pump 5 and the variably operable second drive pump 7. Here, the first drive pump 5 is designed for variable operation with the at least one variably settable first pump parameter P5 and the second drive pump 7 is designed for variable operation, independent of the first pump parameter P5, with the at least one variably settable second pump parameter P7 for generating the variably settable overall drive volumetric flow rate QA of the hydraulic fluid HF in the hydraulic circuit 4. The method comprises the following steps: determining the overall-drive-volumetric-flow-rate target value QAS for the overall drive volumetric flow rate QA, in particular by means of the determination device 50; determining the first parameter target value P5S for the first pump parameter P5 and the second parameter target value P7S for the second pump parameter P7 in a manner dependent on the determined overall-drive-volumetric-flow-rate target value QAS, in particular by means of the determination device 50, where the first parameter target value P5S and the second parameter target value P7S differ from one another if the determined overall-drive-volumetric-flow-rate target value QAS is in the at least one overall-drive-volumetric-flow-rate-target-value range QASB1, QASB2, QASB3, QASB1′ from the set 0, QASB1, QASB2, QASB3, QASB4, QASB1′, QASB2′, QASB3′ of possible overall-drive-volumetric-flow-rate target values QAS; delivering the thick matter DS with the delivery volumetric flow rate QF at the delivery-volumetric-flow-rate target value QFS, in particular by means of the thick-matter delivery system 2, in particular by means of driving the thick-matter delivery system 2 by means of the hydraulic drive system 3, by means of generating the overall drive volumetric flow rate QA with the determined overall-drive-volumetric-flow-rate target value QAS by means of setting the first pump parameter P5 to the determined first parameter target value P5S and the second pump parameter P7 to the determined second parameter target value P7S, in particular and by means of operating the first drive pump 5 and the second drive pump 7, in particular by means of the thick-matter pump 1.

In the exemplary embodiment shown, the hydraulic drive system 3 has only the variably operable first drive pump 5 and the variably operable second drive pump 7. In alternative exemplary embodiments, the hydraulic drive system may have at least three, in particular at least four, variably operable drive pumps.

In detail, the first drive pump 5 and the second drive pump 7 are arranged in parallel in the hydraulic circuit 4.

In addition, the hydraulic drive system 3 has a variably movable drive piston 11 a, 11 b in the hydraulic circuit 4 for driving the thick-matter delivery system 2. The first drive pump 5 and the second drive pump 7 are designed for generating the variably settable overall drive volumetric flow rate QA of the hydraulic fluid HF in the hydraulic circuit 4 for variably moving the drive piston 11 a, 11 b. The method comprises: delivering the thick matter DS by means of variably moving the drive piston 11 a, 11 b.

In the exemplary embodiment shown, the hydraulic drive system 3 has exactly two variably movable drive pistons 11 a, 11 b. In alternative exemplary embodiments, the hydraulic drive system may have only a single variably movable drive piston or at least three, in particular at least four, variably movable drive pistons.

In particular, the hydraulic drive system 3 has a, in the exemplary embodiment shown two, drive cylinders 10 a, 10 b. The drive piston 11 a, 11 b is arranged in the, in particular assigned, drive cylinder 10 a, 10 b.

The hydraulic circuit 4 furthermore has an oscillation line 60.

The first drive pump 5 and the second drive pump 7 and the two drive cylinders 10 a, 10 b form, by means of the oscillation line 60, a closed drive circuit for the hydraulic fluid HF.

Moreover, the two drive pistons 11 a, 11 b are coupled, in particular in antiphase, by means of the oscillation line 60.

Furthermore, the first drive pump 5 and the second drive pump 7 or the closed drive circuit have/has a high-pressure side and a low-pressure side, in particular which are cyclically interchanged with one another, in particular at the time of or during the operation of the thick-matter pump 1.

The thick-matter delivery system 2 moreover has a, in particular at least one, delivery cylinder 12 a, 12 b and a, in particular at least one, variably movable delivery piston 13 a, 13 b for delivering the thick matter DS with the variably settable delivery volumetric flow rate QF. The delivery piston 13 a, 13 b is arranged in the, in particular assigned, delivery cylinder 12 a, 12 b. The method comprises: delivering the thick matter DS by means of variably moving the drive piston 13 a, 13 b.

In particular, the thick-matter pump 1 has a, in particular at least one, piston rod 14 a, 14 b. The piston rod 14 a, 14 b is fastened to the, in particular assigned, drive piston 11 a, 11 b for coupling of movement or transmission of movement to the, in particular assigned, delivery piston 13 a, 13 b.

The method furthermore comprises the step of: determining the delivery-volumetric-flow-rate target value QFS for the delivery volumetric flow rate QF, in particular by means of the determination device 50. The method comprises: determining the overall-drive-volumetric-flow-rate target value QAS in a manner dependent on the determined delivery-volumetric-flow-rate target value QFS.

In particular, the thick-matter pump 1 has a user-operable operator control panel 51 for specification, in particular selection, of the delivery-volumetric-flow-rate target value QFS by a user of the thick-matter pump 1.

The method moreover comprises the step of: detecting a drive-pressure actual value pAI of a drive pressure pA, in particular of a drive high pressure pH, of the hydraulic fluid HF in the hydraulic circuit 4, in particular by means of a, in particular electrical, sensor 40 of the thick-matter pump 1. The drive-pressure actual value pAI of the drive pressure pA is established in a manner dependent on a delivery-pressure actual value pFI of a delivery pressure pF of the thick matter DS at the time of delivery. The method comprises: determining the first parameter target value P5S and the second parameter target value P7S in a manner dependent on the detected drive-pressure actual value pAI.

The thick-matter pump 1 furthermore has at least one drive motor 9, 95, 97. The at least one drive motor 9, 95, 97 is designed for rotating the first drive pump 5 and the second drive pump 7 for generating the overall drive volumetric flow rate QA. The method comprises: delivering the thick matter DS by means of rotating the first drive pump 5 and the second drive pump 7 by means of the at least one drive motor 9, 95, 97.

Moreover, the first drive pump 5 is designed for variable rotation with the first pump parameter P5, in the form of a variably settable first pump rotational speed n5, and the second drive pump 7 is designed for variable rotation, independent of the first pump rotational speed n5, with the second pump parameter P7, in the form of a variably settable second pump rotational speed n7, as shown in FIG. 2 .

In detail, in FIG. 2 , the thick-matter pump 1 has a variably operable first drive motor 95 and a second drive motor 97 which can be operated variably independently of the first drive motor 95. Here, the first drive motor 95 is designed for variably rotating the first drive pump 5, and the second drive motor 97 is designed for variably rotating the second drive pump 7.

In particular, the first drive motor 95 is designed for variably setting its first motor rotational speed n95, and the second drive motor 97 is designed for variably setting its second motor rotational speed n97.

Furthermore, the first drive motor 95 and the second drive motor 97 each have an electric drive motor 105, 107. In particular, the first drive motor 95 and the second drive motor 97 are each an electric drive motor 105, 107.

In FIG. 1 , the thick-matter pump 1 has only a single drive motor 9. In detail, in FIG. 1 , the drive motor 9 has a combustion drive motor 10. In particular, the drive motor 9 is a combustion drive motor 10.

Moreover, in particular in FIGS. 1 and 2 , the first drive pump 5, in the form of a first axial piston pump 5′ having a variably settable first sliding disk 6, is designed for variably setting the first pump parameter P5, in the form of a first pivot angle W6 of the first sliding disk 6, and the second drive pump 7, in the form of a second axial piston pump 7′ having a variably settable second sliding disk 8, is designed for variably setting, independently of the first pivot angle W6, the second pump parameter P7, in the form of a second pivot angle W8 of the second sliding disk 8.

In particular, the hydraulic drive system 3 has at least one, in particular electrically settable, actuator. The at least one actuator is designed for variably setting the first pivot angle W6 and the second pivot angle W8.

In detail, the, in particular only, drive motor 9 is designed for variably setting its motor rotational speed n9. The method comprises the step of: determining a motor-rotational-speed target value n9S for the motor rotational speed n9 in a manner dependent on the determined overall-drive-volumetric-flow-rate target value QAS, in particular and on the detected drive-pressure actual value pAI, as shown in FIGS. 3 and 5 to 7 , in particular by means of the determination device 50. The method comprises: delivering the thick matter DS by means of setting the motor rotational speed n9 to the determined motor-rotational-speed target value n9S, in particular by means of the thick-matter pump 1.

Furthermore, with increasing overall-drive-volumetric-flow-rate target value QAS in a low overall-drive-volumetric-flow-rate-target-value range QASB1, QASB1′, a first pivot-angle target value W6S for the first pivot angle W6 increases, in particular from a first pivot-angle minimum value W6 min of 0%, to a first pivot-angle maximum value W6max, in particular of 100%, and a second pivot-angle target value W8S for the second pivot angle W8 is constant, in particular a second pivot-angle minimum value W8 min of 0%, as shown in FIGS. 6 and 7 . With increasing overall-drive-volumetric-flow-rate target value QAS in a higher overall-drive-volumetric-flow-rate-target-value range QASB2, QASB2′, the second pivot-angle target value W8S increases, in particular from the second pivot-angle minimum value W8 min of 0%, in FIGS. 6 to 80 % and from 80%, and in FIGS. 7 to 50 % and from 50%, up to a second pivot-angle maximum value W8max, in particular of 100%.

In particular and if the first pivot-angle target value W6S is the first pivot-angle maximum value W6max and the second pivot-angle target value W8S is the second pivot-angle maximum value W8max, with increasing overall-drive-volumetric-flow-rate target value QAS in an even higher overall-drive-volumetric-flow-rate-target-value range QASB4, QASB3′, the motor-rotational-speed target value n9S increases from a motor-rotational-speed minimum value n9 min, in FIG. 6 of 70% and in FIG. 7 of 60%, to a motor-rotational-speed maximum value n9max, in particular of 100%.

Moreover, for the graph shown in FIG. 6 , the second axial piston pump 7 generates at the second pivot-angle maximum value W8max of the second pivot angle W8 an overall-drive-volumetric-flow-rate value QAW of the overall drive volumetric flow rate QA that is greater than that which the first axial piston pump 5 generates at the first pivot-angle maximum value W6max of the first pivot angle W6. With increasing overall-drive-volumetric-flow-rate target value QAS in the low overall-drive-volumetric-flow-rate-target-value range QASB1, the first pivot-angle target value W6S for the first pivot angle W6 is greater than the second pivot-angle target value W8S for the second pivot angle W8 up to the first pivot-angle maximum value W6max. With increasing overall-drive-volumetric-flow-rate target value QAS in the higher overall-drive-volumetric-flow-rate-target-value range QASB2, the second pivot-angle target value W8S is greater than the first pivot-angle target value W6S up to the second pivot-angle maximum value W8max.

For the graph shown in FIG. 7 , the second axial piston pump 7 generates at the second pivot-angle maximum value W8max an overall-drive-volumetric-flow-rate value QAW that is equal to that which the first axial piston pump 5 generates at the first pivot-angle maximum value W6max.

In particular, in FIG. 6 , the low overall-drive-volumetric-flow-rate-target-value range QASB1 is greater than 0% to 30% of an overall-drive-volumetric-flow-rate maximum value QAmax. The higher overall-drive-volumetric-flow-rate-target-value range QASB2 is greater than 30% to 40% of the overall-drive-volumetric-flow-rate maximum value QAmax. The even higher overall-drive-volumetric-flow-rate-target-value range QASB4 is greater than 70% to 100% of the overall-drive-volumetric-flow-rate maximum value QAmax. In addition, an overall-drive-volumetric-flow-rate-target-value range 0 lower than the low overall-drive-volumetric-flow-rate-target-value range QASB1 is 0%, and an overall-drive-volumetric-flow-rate-target-value range QASB3 between the higher overall-drive-volumetric-flow-rate-target-value range QASB2 and the even higher overall-drive-volumetric-flow-rate-target-value range QASB4 is greater than 40% to 70%.

In FIG. 7 , the low overall-drive-volumetric-flow-rate-target-value range QASB1′ is greater than 0% to 40% of the overall-drive-volumetric-flow-rate maximum value QAmax. The higher overall-drive-volumetric-flow-rate-target-value range QASB2′ is greater than 40% to 80% of the overall-drive-volumetric-flow-rate maximum value QAmax. The even higher overall-drive-volumetric-flow-rate-target-value range QASB3′ is greater than 80% to 100% of the overall-drive-volumetric-flow-rate maximum value QAmax. In addition, an overall-drive-volumetric-flow-rate-target-value range 0 lower than the low overall-drive-volumetric-flow-rate-target-value range QASB1 is 0%

Furthermore, with increasing overall-drive-volumetric-flow-rate target value QAS in the higher overall-drive-volumetric-flow-rate-target-value range QASB2, the first pivot-angle target value W6S is constant, in particular the first pivot-angle minimum value W6 min of 0%, as shown in FIG. 6 .

Moreover, with increasing overall-drive-volumetric-flow-rate target value QAS in the overall-drive-volumetric-flow-rate-target-value range QASB3, the first pivot-angle target value W6S increases, in particular from the first pivot-angle minimum value W6 min of 0%, in particular to 70% and from 70%, up to the first pivot-angle maximum value W6max.

Furthermore, with increasing overall-drive-volumetric-flow-rate target value QAS in the overall-drive-volumetric-flow-rate-target-value range QASB3, the second pivot-angle target value W8S increases, in particular from 50%, up to the second pivot-angle maximum value W8max.

Moreover, with increasing overall-drive-volumetric-flow-rate target value QAS in the overall-drive-volumetric-flow-rate-target-value range QASB2′, the first pivot-angle target value W6S increases, in particular from 50%, up to the first pivot-angle maximum value W6max, as shown in FIG. 7 .

Consequently, the first parameter target value P5S and the second parameter target value P7S differ from one another if the determined overall-drive-volumetric-flow-rate target value QAS is in the low overall-drive-volumetric-flow-rate-target-value range QASB1, QASB1′ and the higher overall-drive-volumetric-flow-rate-target-value range QASB2, in particular and the overall-drive-volumetric-flow-rate-target-value range QASB3.

In addition, the first parameter target value P5S and the second parameter target value P7S are equal to one another if the determined overall-drive-volumetric-flow-rate target value is in the overall-drive-volumetric-flow-rate-target-value range 0, the higher overall-drive-volumetric-flow-rate-target-value range QASB2′ and the even higher overall-drive-volumetric-flow-rate-target-value range QASB4, QASB3′.

Furthermore, the motor-rotational-speed target value n9S is constant, in particular the motor-rotational-speed target value n9 min, in the overall-drive-volumetric-flow-rate-target-value range 0, the low overall-drive-volumetric-flow-rate-target-value range QASB1, QASB1′, the higher overall-drive-volumetric-flow-rate-target-value range QASB2, QASB2′ and the overall-drive-volumetric-flow-rate-target-value range QASB3.

The method moreover comprises: determining the first parameter target value P5S and the second parameter target value P7S, in particular and the motor-rotational-speed target value n9S, on the basis of an optimization criterion OK, as shown in FIGS. 3 to 5 . The optimization criterion OK is a maximum efficiency q1max of the thick-matter pump 1, in particular a maximum efficiency q2max of the hydraulic drive system 2, in particular a maximum efficiency q5max of the first drive pump 5 and/or a maximum efficiency q7max of the second drive pump 7, or a minimum energy consumption EV9, in particular a minimum fuel consumption KV9, and/or a maximum efficiency q9max of the at least one drive motor 9, 95, 97.

In particular, the user-operable operator control panel 51 is designed for specification, in particular selection, of the optimization criterion OK by the user of the thick-matter pump 1.

In FIG. 3 , the first parameter target value P5S and the second parameter target value P7S, in particular and the motor-rotational-speed target value n9S, are determined by means of a look-up table or offline.

In detail, the look-up table is determined, in particular calculated, by means of characteristic maps, in particular efficiency characteristic maps, of the first drive pump 5 and the second drive pump 7, in particular and of the at least one drive motor 9, 95, 97, for the possible overall-drive-volumetric-flow-rate target values QAS, in particular and possible drive-pressure actual values pAI, as shown in FIG. 4 .

In FIG. 5 , the first parameter target value P5S and the second parameter target value P7S, in particular and the motor-rotational-speed target value n9S, are determined, in particular calculated, online by means of, in particular the, characteristic maps of the first drive pump 5 and the second drive pump 7, in particular and of the at least one drive motor 9, 95, 97.

Furthermore, the determination device 50 has a, in particular electrical, signal connection to the first drive pump 5 and the second drive pump 7, in particular by means of the at least one actuator, in particular and to the operator control panel 51, the sensor 40 and the at least one drive motor 9, 95, 97.

As is made clear by the exemplary embodiments shown and discussed above, the invention provides an advantageous method for operating a thick-matter pump and an advantageous thick-matter pump that in each case have improved properties. 

1.-15. (canceled)
 16. A method for operating a thick-matter pump, wherein the thick-matter pump comprises: a thick-matter delivery system designed to deliver thick matter with a variably settable delivery volumetric flow rate, and a hydraulic drive system, wherein, for driving the thick-matter delivery system, the hydraulic drive system has: a hydraulic circuit having a hydraulic fluid, a variably operable first drive pump, and a variably operable second drive pump, wherein the first drive pump is designed for variable operation with at least one variably settable first pump parameter and the second drive pump is designed for variable operation, independent of the first pump parameter, with at least one variably settable second pump parameter for generating a variably settable overall drive volumetric flow rate of the hydraulic fluid in the hydraulic circuit, the method comprising the steps of: determining an overall-drive-volumetric-flow-rate target value (QAS) for the overall drive volumetric flow rate (QA), determining a first parameter target value (P5S) for the first pump parameter (P5) and a second parameter target value (P7S) for the second pump parameter (P7) in a manner dependent on the determined overall-drive-volumetric-flow-rate target value (QAS), wherein the first parameter target value (P5S) and the second parameter target value (P7S) differ from one another when the determined overall-drive-volumetric-flow-rate target value (QAS) is in at least one overall-drive-volumetric-flow-rate-target-value range (QASB1, QASB2, QASB3, QASB1′) from a set (0, QASB1, QASB2, QASB3, QASB4, QASB1′, QASB2′, QASB3′) of possible overall-drive-volumetric-flow-rate target values (QAS), and delivering the thick matter (DS) with the delivery volumetric flow rate (QF) at a delivery-volumetric-flow-rate target value (QFS) by way of generating the overall drive volumetric flow rate (QA) with the determined overall-drive-volumetric-flow-rate target value (QAS) by setting the first pump parameter (P5) to the determined first parameter target value (P5S) and the second pump parameter (P7) to the determined second parameter target value (P7S).
 17. The method as claimed in claim 16, further comprising the steps of: determining the delivery-volumetric-flow-rate target value (QFS) for the delivery volumetric flow rate (QF), and determining the overall-drive-volumetric-flow-rate target value (QAS) in a manner dependent on the determined delivery-volumetric-flow-rate target value (QFS).
 18. The method as claimed in claim 16, further comprising the steps of: detecting a drive-pressure actual value (pAI) of a drive pressure (pA), of the hydraulic fluid (HF) in the hydraulic circuit, wherein the drive-pressure actual value (pAI) of the drive pressure (pA) is established in a manner dependent on a delivery-pressure actual value (pFI) of a delivery pressure (pF) of the thick matter at the time of delivery, and determining the first parameter target value (P5S) and the second parameter target value (P7S) in a manner dependent on the detected drive-pressure actual value (pAI).
 19. The method as claimed in claim 16, wherein the thick-matter pump has at least one drive motor, wherein the at least one drive motor is designed for rotating the first drive pump and the second drive pump for generating the overall drive volumetric flow rate, and the method further comprising the step of: delivering the thick matter by rotating the first drive pump and the second drive pump via the at least one drive motor.
 20. The method as claimed in claim 16, wherein the first drive pump is designed for variable rotation with the first pump parameter (P5), in the form of a variably settable first pump rotational speed (n5), and the second drive pump is designed for variable rotation, independent of the first pump rotational speed (n5), with the second pump parameter (P7), in the form of a variably settable second pump rotational speed (n7).
 21. The method as claimed in claim 19, wherein the thick-matter pump has a variably operable first drive motor, and a second drive motor which is operatable variably independently of the first drive motor, wherein the first drive motor is designed for variably rotating the first drive pump, and the second drive motor is designed for variably rotating the second drive pump.
 22. The method as claimed in claim 21, wherein the first drive motor and the second drive motor are electric drive motors.
 23. The method as claimed in claim 19, wherein the at least one drive motor is a combustion drive motor.
 24. The method as claimed in claim 16, wherein the first drive pump, in the form of a first axial piston pump having a variably settable first sliding disk, is designed for variably setting the first pump parameter, in the form of a first pivot angle of the first sliding disk, and wherein the second drive pump, in the form of a second axial piston pump having a variably settable second sliding disk, is designed for variably setting, independently of the first pivot angle, the second pump parameter, in the form of a second pivot angle of the second sliding disk.
 25. The method as claimed in claim 19, wherein the at least one drive motor is designed for variably setting its motor rotational speed, the method further comprising the steps of: determining a motor-rotational-speed target value (n9S) for the motor rotational speed (n9) in a manner dependent on the determined overall-drive-volumetric-flow-rate target value (QAS), and delivering the thick matter by way of setting the motor rotational speed (n9) to the determined motor-rotational-speed target value (n9S).
 26. The method as claimed in claim 18, wherein the at least one drive motor is designed for variably setting its motor rotational speed (n9), the method further comprising the steps of: determining a motor-rotational-speed target value (n9S) for the motor rotational speed (n9) in a manner dependent on the determined overall-drive-volumetric-flow-rate target value (QAS) and on the detected drive-pressure actual value (pAI), and delivering the thick matter (DS) by way of setting the motor rotational speed (n9) to the determined motor-rotational-speed target value (n9S).
 27. The method as claimed in claim 24, wherein, with increasing overall-drive-volumetric-flow-rate target value (QAS) in a low overall-drive-volumetric-flow-rate-target-value range (QASB1, QASB1′), a first pivot-angle target value (W6S) for the first pivot angle (W6) increases up to a first pivot-angle maximum value (W6max) and a second pivot-angle target value (W8S) for the second pivot angle (W8) is constant, and in a higher overall-drive-volumetric-flow-rate-target-value range (QASB2, QASB2′), the second pivot-angle target value (W8S) increases up to a second pivot-angle maximum value (W8max), and if the first pivot-angle target value (W6S) is the first pivot-angle maximum value (W6max) and the second pivot-angle target value (W8S) is the second pivot-angle maximum value (W8max), in an even higher overall-drive-volumetric-flow-rate-target-value range (QASB4, QASB3′), the motor-rotational-speed target value (n9S) increases from a motor-rotational-speed minimum value (n9 min) up to a motor-rotational-speed maximum value (n9max).
 28. The method as claimed in claim 24, wherein the second axial piston pump generates, at a second pivot-angle maximum value (W8max) of the second pivot angle (W8), an overall-drive-volumetric-flow-rate value (QAW) of the overall drive volumetric flow rate (QA) that is greater than that which the first axial piston pump generates at a first pivot-angle maximum value (W6max) of the first pivot angle (W6), and wherein, with increasing overall-drive-volumetric-flow-rate target value (QAS) in a low overall-drive-volumetric-flow-rate-target-value range (QASB1), a first pivot-angle target value (W6S) for the first pivot angle (W6) is greater than a second pivot-angle target value (W8S) for the second pivot angle (W8) up to the first pivot-angle maximum value (W6max), in a higher overall-drive-volumetric-flow-rate-target-value range (QASB2), the second pivot-angle target value (W8S) is greater than the first pivot-angle target value (W6S) up to the second pivot-angle maximum value (W8max), and if the first pivot-angle target value (W6S) is the first pivot-angle maximum value (W6max) and the second pivot-angle target value (W8S) is the second pivot-angle maximum value (W8max), in an even higher overall-drive-volumetric-flow-rate-target-value range (QASB4), the motor-rotational-speed target value (n9S) increases from a motor-rotational-speed minimum value (n9 min) up to a motor-rotational-speed maximum value (n9max).
 29. The method as claimed in claim 19, further comprising the steps of: determining the first parameter target value (P5S) and the second parameter target value (P7S), on the basis of an optimization criterion (OK), wherein the optimization criterion (OK) is a maximum efficiency (q1max) of the thick-matter pump.
 30. The method as claimed in claim 29, wherein the optimization criterion (OK) is a maximum efficiency (q2max) of the hydraulic drive system or a minimum energy consumption (EV9), and/or a maximum efficiency (q9max) of the at least one drive motor.
 31. The method as claimed in claim 16, wherein the first drive pump and the second drive pump are arranged in parallel in the hydraulic circuit, and/or wherein the hydraulic drive system has a variably movable drive piston in the hydraulic circuit for driving the thick-matter delivery system, wherein the first drive pump and the second drive pump are designed for generating the variably settable overall drive volumetric flow rate of the hydraulic fluid in the hydraulic circuit for variably moving the drive piston, and the method further comprising the step of: delivering the thick matter by way of variably moving the drive piston.
 32. A thick-matter pump, comprising: a thick-matter delivery system, wherein the thick-matter delivery system is designed for delivering thick matter with a variably settable delivery volumetric flow rate; and a hydraulic drive system, wherein, for driving the thick-matter delivery system, the hydraulic drive system comprises: a hydraulic circuit having a hydraulic fluid, a variably operable first drive pump, and a variably operable second drive pump, wherein the first drive pump is designed for variable operation with at least one variably settable first pump parameter (P5) and the second drive pump is designed for variable operation, independent of the first pump parameter (P5), with at least one variably settable second pump parameter (P7) for generating a variably settable overall drive volumetric flow rate (QA) of the hydraulic fluid in the hydraulic circuit; and a determination device, wherein the determination device is configured to: determine an overall-drive-volumetric-flow-rate target value (QAS) for the overall drive volumetric flow rate (QA), and determine a first parameter target value (P5S) for the first pump parameter (P5) and a second parameter target value (P7S) for the second pump parameter (P7) in a manner dependent on the determined overall-drive-volumetric-flow-rate target value (QAS), wherein the first parameter target value (P5S) and the second parameter target value (P7S) differ from one another if the determined overall-drive-volumetric-flow-rate target value (QAS) is in at least one overall-drive-volumetric-flow-rate-target-value range (QASB1, QASB2, QASB3, QASB1′) from a set (0, QASB1, QASB2, QASB3, QASB4, QASB1′, QASB2′, QASB3′) of possible overall-drive-volumetric-flow-rate target values (QAS), and wherein the thick-matter pump is designed for delivering the thick matter with the delivery volumetric flow rate (QF) at a delivery-volumetric-flow-rate target value (QFS) by generating the overall drive volumetric flow rate (QA) with the determined overall-drive-volumetric-flow-rate target value (QAS) by setting the first pump parameter (P5) to the determined first parameter target value (P5S) and the second pump parameter (P7) to the determined second parameter target value (P7S). 